Sewing machine construction



March 3, 1953 H,v. KlNnsETH r-:rAL 2,630,086

SEWING MACHINE CONSTRUCTION Filed Jan. 5, 1951 4 Sheets-Sheet l E #4420.4 o A. /C'ox (Ittornegf March 3, 1953 H. v. KINDSETH ETAL 2,630,085

SEWING MACHINE CONSTRUCTION Filed Jan. 5, 1951 4sheets-sneet 2 Gttomegs March 3, 1953 H. v. KlNnsETH ETAL 2,530,086

sEwINC MACHINE CONSTRUCTION Filed Jan. 5, 1951 4 sheets-sheet 5 /fqo AT Fox Gttornegs March 3, 1953 H. v. KINDSETH r-:rAL 2,630,086

SEWING MACHINE CONSTRUCTION Filed Jan. 5, 1951 4'Sheets-Sheet 4 Gttornegs Patented Mar. 3, 1953 UNITED STATES PATENT OFFICE SEWING MACHINE CONSTRUCTION Harold V. Kindseth and Harold K. Fox, Minneapolis,` Minn., assignors to Bemis Bro. Bag Co., Minneapolis, Minn., a corporation of Missouri Application January 5, 1951, serial No. 204,526

:i claims. (c1. i12- 11)` Our invention relates generally to power driven sewing machines and more specifically to improvements in machines utilized in stitching closed the upper ends of iilled bags.

In machines of this type heretofore used, it was necessary for the operator to manually st-art the sewing machine by means of a hand lever, foot operated pedal or the like, guide the bag manually through the machine, particularly when sewing cloth bags and manu-ally operate thread-cutting means whereby to provide a length of stitching on opposite sides of the bag. These multiple operations frequently throw theV operator off balance and result in an uneven line of stitching and cause undue fatigue. Manual operation of machines of the -above type have the further disadvantage of often resulting in uneven lengths of stitched thread projecting from opposite sides of the bag. In some instances, the projected portion of the stitched thread is too short to provide adequate protection against raveling; in others, the projected portion may be of a length sufcient to present an untidy ap` pearance tov the nished product.

`An important object of our invention is the provision of a power driven sewing machine of the type set forth having means for automatically initiatingffeeding and sewing operations when a lled bag is introduced thereinto and for automatically stopping thefeeding and sewing operations after the bag hasI been fed through the sewing machine.

Another important object of our invention is the provision of automatic means for severing the stitched thread in uniform outwardly spaced relationship to the stitched closed bags.

Still another object of our invention is the provision of means for severing the stitched thread and means for automatically moving the stitched thread into engagement with the threadcutting means.

`A still further object of our invention is the provision of means for aiding in the support of the upper ends of cloth bags fed through the sewing machine during the stitching operation.

Another` object of our invention is the provision of a machine of the `type set forth which can with equal facility sew together the upper ends of cloth or paper bags. A l l Y Another object of our invention is the provision of an attachment which may be applied to sewing machines of the kind set forth for automatically severing the stitched thread in out` wardly spacedrelation tothe opposite sides of. a bag sewed therein.

2 Another object of our invention is the provision ofapparatus for controlling machines of the above type, and for automatically cutting stitched thread as set forth, which is relatively simple and inexpensive to manuafcture, which is highly efcient in operation and which is rugged in con` struction' and durable in use.

' The above and still further highly important objects and advantages of our invention will become apparent from the following detailed specication, appended claims, and attached drawings.

Referring to the drawings, which illustrate the invention, and in which like characters indicate like parts throughout the several views:

Fig. l is a fragmentary view in side elevation, some parts being broken away and some parts being shown in section, of a power driven sewing machine and controls therefor, built in accord` ance with our invention;

Fig. 2 is an enlarged fragmentary section taken substantially on the line 2-2 of Fig. 1;

Fig. 3 is a still further enlarged fragmentary detail partly in elevation and partly in section taken substantially on the line 3--3 of Fig. 2;

Fig. 4 is a View corresponding to Fig. 2` but showing a different position of some of the parts;

Fig. 5 is a View corresponding to Fig. 2 but showing a still different position of some of the parts;

Fig. 6 is an enlarged fragmentary section taken substantially on the line 6 6 of Fig. 5;

Fig. '7 isV a. fragmentary detail as seen from the line 1-1 of Fig. 5; and

Fig. 8 `is a wiring diagram.

Referring with greater detail to the drawings, numeral i indicates in its entirety a power driven sewing machine having `a base 2 and a sewing head 3. The head 3 sup-ports a needle li by means of a conventional reciprocating needle bar 5 and a presser foot 6 secured to the inner end of al presser rod or shaft 'I'. The sewing and feeding mechanism of the machine is of conventional nature and is shown in the drawings more or less diagrammatically. However, it willl be seen, by reference to Figs. 1, 2, 4 and 5, that the needle bar 5 and feedingmechanism are driven from a drive shaft 8,` the needle bar 5 being operatively connected theretorby an eccentric operated pitman rod 9 and lever i0 pivoted tothe machine l, asindicated at H, and connected at,V

one end to the pitman arm `lil and at its other end suitably connected to the outer` endV of the needle bar 5. The feeding mechanism comprises an eccentric l2 on the shaft Band a pitman arm'` I3 driven by the eccentric l2 and connected at its free end to a crank arm I4 fast on a rock shaft I5. Therock shaft I5 is suitably journalled in the base 2 and has rigidly secured thereto a crank arm I6 which drives a pair of serrated feed dogs I1 Iand I8 through a rigid link I9. The feed dogs I1 and I8 extend laterally outwardly through apertures in a base plate 2I suitably mounted on the base 2. The feed dogs I1 and I8 are adapted to move in a direction to feed an article to be stitched between the base plate 2l and the presser foot 6 from the right to the left with respect to Figs. 2, 4 and 5.

The frame I of the sewing machine is rigidly secured to a mounting bracket 22 which is supported from a main supporting frame 23 Vby laterally extending arms 24, one of which is shown. A drive motor 25 is rigidly mounted on the upper end of the bracket 22 and drives the sewing and feeding mechanism through a V-belt 26 run' ning over a V-pulley 21 associated with the drive shaft of the motor 25 and another pulley 28 mounted fast on the drive shaft 8. By reference to Fig. l, it will be seen that the pulley 21 is provided with a clutch mechanism 29 which is controlled by a clutch lever 30 to operatively couple the pulley 21 to the motor 25. The clutch lever 30 is pivoted intermediate its ends to an arm 3I depending from the base of the motor 25'. At its free end, the lever is secured by a coupling 32 to a plunger 33 operated by a solenoid 34, see Figs. 1 and 8. The solenoid 34 is contained within a housing 35 secured to the base of the motor 25 and supported by the upper end of the bracket 22. The lever 30 is further provided with a spring 36 which biases the clutch 29 toward its inoperative position shown by dotted lines in Fig. 1, and an adjustable stop element 31. The clutch and operating linkage therefor do not in themselves constitute the invention land further detailed description thereof is thought unnecessary.

The clutch-controlling solenoid 34 is operated by a switch 38 contained within a housing 39 mounted on a bracket 48 that is suitably secured to the base member 2. The switch 38 is of a conventional type which permits overtravel of the switch outwardly after the contacts of the switch have been closed. A plunger-type switch button 4I extends outwardly of the housing 38 and is yieldingly biased against inward switchclosing movements by a spring 42 having one end engaging a flange portion or the like 43 on the plunger 4I. The switch 38 may be assumed to be in a normally opened position, the closing thereof being effected by inward movement of the actuator 4I against bias of the spring 42. As seen in Fig. 8, the switch 38 is interposed in a circuit comprising a lead 44 connected to opposite sides of a suitable source of electrical power such as a power line 45. The solenoid 34 is also interposed in the lead 44 in series with the switch 38 so that'when the switch 38 is closed, the circuit is completed through said solenoid 34.

The bracket is provided atits outer end laterally outwardly of the switch housing 39 with an upstanding bearing sleeve 46 in which is journalled for rotation a shaft 41 'to the lower end of which is rigidly secured a bag top engaging Vfinger or the like 48. The finger 48' lies below the plane of the lower end of the base 2 and is swingable into and out of the path of travel of a bag or article to be stitched during feeding movements thereof through the machine. finger 48 is provided with anV upstanding camlike element 49 which presents a relatively wide surface to the upper end portion of the bag to be sewn, said bag being indicated by A and the closed upper end thereof being indicated by the character B. An abutment lug or plate 50 is welded or otherwise rigidly secured to the camlike element 49 and is positioned to engage the switch button 4I and operate the same upon swinging movements of the finger 48. It will be noted that the spring 42 biases the finger 48 toward a normal position underlying the presser foot 6 and interposed in the path of travel of the bags A'and that the leading end portion of the presser foot 6 diverges from the finger 48. Thus, when abag A is fed into the machine in a direction from the right to the left with respect to Figs. 2, 4 and 5, a wedging action will be imparted to the diverging portion of the presser foot 6 and the finger 48 by theY upper end portion B of the bag. This wedging action will cause the finger 48 to be swung laterally out of the path of travel of the upper bag and B whereby to close the switch 38 thus energizing the solenoid and causing the clutch 29 to operatively couple the stitching and feeding mechanism to the motor 25.

Rigidly secured to the presser foot 6 is a presser bar 5I which extends longitudinally of the direction of feeding movement of the bag A and which is provided with a longitudinally extended channel 52 which receives the free end portionV 48' of the finger 48 when said finger is in its normal position. The presser bar 5I lies against one side of the upper bag end B and braces the same against the tendency of the finger 48 to swing to its normal position. The presser bar 5I is particularly effective in the sewing of bags A which are made from relatively flimsy material such as cloth or the like which may tend to buckle under the lateral pressure exerted thereagainst by the free end portion 48 of the finger 48 and permit the switch 38 to be opened, thus stopping the stitching and feeding action before the bag is completely stitched.

The sewing machine which is preferably of a type which produces a chain stitch is provided with a thread-cutting mechanism including a pair of cooperating stationary and movable cutting knives 53 and 54, respectively. The sta'-V tionary knife or blade 53 is mounted on a bracket 55 in the base 2 by meansof a clamping screw 56. The movable blade 54 is adjustably secured by means of a clamping screw or the like 51 to one end of a mounting arm 58 which at its other end is pivotally secured, as indicated at 59, tov

a bearing boss or the like 69 integrally formed with the base 2. The arm 58 intermediate its ends is formed to provide a laterally projecting nger 6I to the end of which isrpivotallysecured one end of a rigid link 62. At the other end, the link 62 is pivoted to a bifurcated swivel member 63 pivotally mounted on one end of a lever arm 64 which at its'intermediate portion is -mounted for swinging movements to a bracket 65. `At its other end, the lever 64 is provided with a follower stud 66 which engages a cam 66' fast on the shaft 8. Rotation ofthe shaft 8 in a direction to operate the feed dogs I1 and I8 and the stitch ing mechanism will cause oscillatory movements to be imparted tothe movable blade 54 toward and away from operative engagement with the relatively fixed cutting blade 53. With reference to Figs. 2 and 4 to '7 inclusive, it will be seen that the cutting blades 53 and 54 operate in laterally offset relation to the plane of the material being esst-,css

stitched through the machine; It should be al# so noted that cutting movement of the movable blade 54 is continuous with the stitching and feeding operatiensand terminates simultaneously with eessation f the Stitching and feeding operations. The base plate 2| is provided with a longitudinally extended slot 2 I which bifureates the plate 2| at its rear end portion. The slot 2l' is in registration with an opening 51 in lthe base 2 adjacent which opening the thread cutting blades 53 and 54 operate.

Heretofore, when it has been desired to sever the stitched thread, indicated by the letter G, it has been necessary for the operator of the mae chine to manually move the stitched thread C laterally through the slot 2| and opening 6l into the path of travel of the movable cutter blade 54. In the sewing of bags of the type herein illustrated, it is 'common practice to sever the stitched thread C in outwardly spaced relation'- ship to the opposite sides of the bag A so that an appreciable length of stitched thread remains on said opposite sides. Manual control of the cutting of the stitched thread C not only is fatiguing to the operator but often results in said stitched thread portions being of uneven length. As above indicated, an insufiicient length of stitched thread C extending outwardly from a side of the bag will sometimes ravel to an extent where a portion Vof the bag will become open, resulting in possible leakage 'of the contents therefrom. On the other hand, excessive length of the stitched thread C projecting from `the side of the bag will present an untidy appearance and may result in entanglement with other portions of the bag handling equipment and the like. We provide, therefore, means for automatically moving the stitched thread C into engagement with the cutting blades 53 and 5'4 ina manner to produce lengths of stitched thread extending outwardly from opposite sides of the bag, said stitched threads being of suihcient uniform length to prevent ravelling. The above-mentioned mechanism comprises a movable member in the nature of an elongated reciprocatory bar 68 mounted for reciprocatory sliding movements in a bracket 69 having spaced laterally projecting lugs 'Eil and H integrally formed therewith. A mounting rod or shaft l2 extendst'hrough suitable openings in the lugs 'l0 and 1l and through cooperating lugs i3 and I4 on the sewing machine. rIhe bar 68 is provided at one end with a tliread-engaging head comprising a pair of prongsror fingers 'i 5 which diverge longitudinally outwardly of the bar 68 and generally in the direction oi' the thread-cutting mechanism. Upon longitudinal movement of the bar 68 toward the thread C, the fingers 15 engage and gather in the stitched thread C moving the same laterally inwardly through the slot 2l in the base plate 2| and the opening B1 in the base 2. With reference to Figs. 2, 4 and 5, it will be seen. that the bar 68 is in spaced relationship to Vthe cutting blades 53 and 54 in the direction of feeding movement of the bags through the machine. At its opposite end, the bar 68 is Vrigidly secured to one end of a flexible push rod 'I6 by means of a set screw or the like 11. The push rod 'i6 is encased within a eXible tubular casing 'i8 which is clamped between clamping ears i9 at the adjacent end of the bracket 69. At its opposite end, the push rod i6 is rigidly secured to one end of an arm 80 which, at its other end, is mounted fast on a portion of the stop element 3l of the clutch operating lever 30 for common 6. swing-ing'movements with said lever 30. The cable housing 'IB is Supported intermediate its endsby suitable brackets or the like 8l and B2 the former of which is rigidly secured to a portion of the bracket 22 and the other of which is `secured to the sewing machine I. With reference to Fig. 1, it will be seen that solenoid controlled movement of the lever arm 30 in a direction to cause operative coupling of the stitching and feeding mechanism to the motor 25 will cause longitudinal sliding movement of the bar 68 in a retracted direction lgenerally away 'from the cutting knives or blades 53 and 54, whereas movement of the lever 30 in a direction to disengage the clutch 29 will cause longitudinal sliding movement of the bar 68 in a direction to permit the fingers i5 to pick up the stitched thread C and move the same into engagement with the cutting blades.

Operation Assuming that the motor 25 is suitably connected to a source of power and operating continuously, the operator feeds or causes to be fed to the sewing machine a filled bag A. Movement of the upper closed end B of the bag A toward the stitching means causes said upper end to be wedged between the presser foot `l5 and the switch operating :finger 48 with resultant Vswinging movement of the finger 48 in Ya direction to `close -the switch 38. When the switch 33 is closed, a circuit through the lsolenoid 34 `is completed to lenergire the solenoid 34 causing movement oi" the clutch -29 `toward a clutch-engaged position to start `the stitching and feeding operation. The feed dogs `Il fand I8 then cause the bag to go through the `'machine `-and the upper end thereof is stitched closed, the stitching and feeding operation continuing until the 'upper end portion .B of the bag progresses beyond the .free end 48 of the ngerli, whereupon the 4iinger 48 will return under bias `of the spring `l2 to its .normal position of Fig. 2. This return movement of the finger 138 Vopens the-switch 38 and uncouples the drive motor 25 from the stitching and feeding mechanism of the machine, the above-mentioned uncoupling being eiected by the pressure exerted on the lever 30 by the spring 42. lit should be assumed that the bag A is supported during its travel through the machine by conveyor means, not shown, said conveyor means preferably being of the type disclosed in the United States patent to Daniel Belcher et al., No. 2,423,080, issued July 1, 1947. Hence, after the stitching operation is completed, the bag Acontinues to move with respect to the'sewing mechanism, trailing a length of stitched thread C. It should be borne in :mind that release of the clutch 29 does not cause mmediate termination of operation of the sewing vand feeding mechanism, the mechanism decelerating to a stop after the clutch 29 has been disengaged. It is at the beginning -of this deceleration period that the thread C fis moved into engagement with the cutting blades 53 and 54 by the bar ES and severed bysaid knives. The bag A travels sufhcient distance beyond the trailing end 48 of the finger 48, after releasing the iinger 48, to insure an adequate length of stitched thread C to extend therefrom before the thread is severed by the cutting blades. The distance between the cutting blades and the needle 4 provides for an adequate length of stitched thread to project outwardly from the leading edge of the next successive bag to be stitched.

From the above, it should be obvious 'that bags sewecl in accordance with our invention will have lengths ofstitched thread projecting from the opposite sides thereof that are uniform and that the automatic cutting of the thread will result in a savings in thread as well as preventing undue fatigue of the operator, it being merely necessary for the operator to feed bags to the feeding mechanism in spaced relationship. The switch 38 and actuator finger l therefor as well as the mechanism for automatically moving the thread into engagement with the cutting knives may be readily applied to existing stitching equipment with a minimum of .change made in said equipment.

Our invention has been tested on a commercial basis and has been found to be completely satisfactory for the accomplishment of the objectives set forth; and, while we have shown and described a preferred embodiment thereof, it will be understood that the same is capable of modication and that modification may be made without departure from the spirit and scope of the invention as dei-ined in the claims.

What we claim is:

1. An attachment for sewing machines having means for stitching articles successively fed in spaced relation, means including a clutch mechanism for operating the stitching means, mechan ism for cutting the stitching thread outwardly of opposite sides of said articles, and bag actuated control means for said operating means; said attachment including an elongated reciproatory,

member, a fork-like head on said member, said head comprising a pair of iin-gers diverging longitudinally outwardly of one end of said member, bracket means mounting said member for longitudinal reciprocatory movements whereby the head thereof crosses the path of travel of the stitching thread in spaced relation to the stitching means, and a ileXible push rod connected at one end to said reciprocatory member and having means on its other end for connection to a portion of said clutch mechanism to be longitudinally moved thereby in opposite directions, said movement being transferred by said push rod to said reciprocatory member.

2. In a sewing machine, means for stitching articles successively fed in spaced relation, said means including a base plate and a sewing head,

said head having va presser foot and cooperating needle, means for feeding said articles intermediate said base plate and said presser foot in the direction of feeding movement of said articles, means positioned beyond the needle in the line of feed for cutting the stitching thread outwardly of opposite sides of said articles, means including clutch mechanism for simultaneously imparting sewing movements to the needle, feeding movements to the feeding means and cutting movements to the cutting means, common control means for said needle, article feeding means and cutting means, said control means comprising a clutch actuating solenoid and a switch therefor, a finger normally lying in a position within the path of travel of said articles adjacent said presser foot and biased toward said position, said nger being movable by said articles to operate said switch, and means for moving the stitching thread into engagement with the thread-cutting means responsive to operation of said control means to stop the stitching, feeding and cutting mechanisms, said means formoving the stitching thread into engagement with the cutting means comprising a movable member, a thread-engaging head on said movable member, means mounting said movable member for movements across the path of travel of the stitching thread, and a flexible push rod connected at one end'to said movable member and at its other end to a movable portion of said clutch mechanism for transferring movement of said movable portion to said movable member.

3. In a sewing machine, means for stitching articles successively fed in spaced relation, said means including a base plate and a sewing head, said head having a presser foot and cooperating needle, means for feeding said articles intermediate said base plate and said presser foot in the direction of feeding movement of said articles, means positioned beyond the needle in the line of feed for cuttingI the stitching thread outwardly of opposite sides of said articles, means for simultaneously imparting sewing movements to the needle, feeding movement to the feeding means and cutting movements to the cutting means, common control means for said needle, article feeding means and cutting means, said control means comprising a clutch actuating solenoid and a switch therefor, a nger normally lying in a position within vthe path of travel of said articles adjacent said presser foot and biased toward said position, a presser bar mounted on said presser foot and having a channel receiving a portion of said finger when said nger is in its normal position, said finger being movable out of said channel by said articles to operate said switch, and means for moving the stitching thread into engagement with the thread-cutting means responsive to operation of said control means to stop the stitching, feeding and cutting mechanism, said means for moving the stitching thread into engagement with the cutting means comprising a movable member, a thread-engaging head on said movable member, means mounting' said movable member for movements across the path of travel of the stitching thread, and connections between said movable member and a movable portion of said control means for transferring movement of said movable portion to said movable member.

HAROLD V. KINDSETH. HAROLD K. FOX.

REFERENCES CITED The following references are of record inthe ille of this patent:

UNITED STATES PATENTS Number Name Date 2,262,294 Merrifield Nov. 11, 1941 2,282,200 Neuman May 5, 1942 2,293,686 Allen Aug. 18, 1942 2,539,627 Kindseth et al Jan. 30, 1951 

